Flexible Swing Stick Impact Simulator and Muscle Trainer

ABSTRACT

A flexible swing stick is provided comprising a hollow tube with a distal end and a proximal end wherein at least the distal end is closed by an integral seal. At least one slidably received weight is in the hollow tube with the weight disposed to move from the proximal end to the distal end when the flexible swing stick is swung through a range of motion. The proximal end is closed, preferably by an integral seal.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to pending U.S. ProvisionalPatent Application No. 62/917,380 filed Dec. 3, 2018 which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention is related to an improved flexible swing stick,and method of use, wherein the flexible swing stick allows for thetraining of muscles and proprioceptors associated with the swinging of aclub such as those clubs used in various sports.

BACKGROUND

Advances in the ability of an athlete to swing a club more efficientlyand consistently have been ongoing since the development of the firstsporting activity utilizing a club. Many sports utilize a club of somesort such as baseball, softball, golf, cricket, tennis, badminton,lacrosse, field hockey, ice hockey, racquetball, squash, pickleball,table tennis and the like. In each instance there is a point of contactbetween the club and ball, or object, wherein the point of contact iswithin a narrow portion of a larger range of motion. It is mostpreferable that the point of contact consistently occurs within thenarrow portion wherein within that narrow portion of the range of motionthe speed of the club is at a maximum. The increased speed within thenarrow portion of the range is typically due to some activity of theathlete such as a rapid movement of the wrist within that narrow portionof the range of motion. For the purposes of illustration and withoutlimit thereto, during a baseball swing the initial portion of themovement of the baseball bat is primarily a function of the rotation ofthe torso and rotation of the arms with virtually no use of the wrist.As the bat approaches the narrow portion of the range of motion, whichis preferably over home plate or the preferred hitting zone, theinvolvement of the wrist significantly increases the speed of the batthrough the hitting zone, which represents the narrow portion, therebymaximizing the impact force of the bat on the ball. Similar motionsoccur in virtually any sport wherein a ball or object is impacted by amoving club.

The precision of that portion of the swing wherein the torso, arms andwrist are all simultaneously involved, which is preferably within thenarrow portion, determines the effectiveness of the swing. However,training the muscles to be at maximum effectiveness through the narrowportion of the range of motion is difficult as any motion of one part ofthe body may impact the timing and effectiveness of other portions ofthe body. Again, with reference to swinging a baseball bat for thepurposes of discussion without limit thereto, if the torso rotates tooquickly the arms may reach the intended hitting zone out of sync withthe body and therefore the wrist rotation occurs prior to the bat beingin the narrow portion of the larger range of motion resulting in a missor a weak hit.

There has been a long-standing desire for a device for training anathlete to swing a club more precisely. Many attempts with an actualball or object are normally employed, however, it is not uncommon forpositive feed-back on poor swing mechanics to be realized resulting inthe reinforcement of bad swing mechanics. By way of example, again withreference to baseball, a hard-hit foul ball may feel to the batter as ifthe ball was well struck even though the timing of the swing, or swingmechanics, may be responsible for the ball being out of play. Similarly,in golf, a hook or slice may feel well struck to the golfer. In eachcase, a limiting environment of practice, such as a batting cage orhitting into a net, may mask the true trajectory of the path of the ballthereby providing positive feedback on what is otherwise a flawedswinging motion. Furthermore, it is difficult to train the musclesadequately when actually striking a ball or object since any variationfrom optimum mechanics can cause injury.

The present invention, and methods of using the invention, provides anability to improve the swinging of a club while simultaneouslystrengthening the appropriate muscles and training the appropriateproprioceptors.

SUMMARY OF THE INVENTION

The present invention is related to an enhanced training device and asystem of training which is particularly suitable for training thesensory receptors, or proprioceptors, by providing the vestibularfeedback of sound thereby enabling effective adjustments to motion toachieve a more effective swinging motion for the sport being played.

It is another object of the invention to provide an improved trainingdevice, and methods of use, for training the neuromuscular system thatcontrols the movement of an athlete's wrists, hands, arms and upper bodyso the athlete can swing a club with greater speed, control, consistencyand more explosive force.

A particular feature of the invention is the ability to train, withspecificity, the fast twitch muscles that control wrist, hand and armmovement involved in swinging a club.

It is another object of the invention to train the sensory receptors, orproprioceptors, in the muscles and tendons to improve awareness of therelative position of the joints controlled by these muscles and tendonsthereby enhancing dynamic joint stability which enables the individualto perform swinging movements more effectively.

It is another object of the invention to provide the user with a devicethat can be swung like a club to simulate the sound and feel of hittinga ball, or object, without actually having to hit a ball or objectthereby providing the user with the vestibular feedback of feel andsound which can be beneficial for the trainer and individual in trainingfor an improved swing. The sound and feel can be correlated with theoptimum position of the hands and wrists during the swinging motionthereby allowing the individual to alter their swing to create animproved swing with a different feel and sound.

These and other embodiments, as will be realized, are provided in aflexible swing stick comprising a hollow tube with a distal end and aproximal end wherein at least the distal end is closed by an integralseal. At least one slidably received weight is in the hollow tube withthe weight disposed to move from the proximal end to the distal end whenthe flexible swing stick is swung through a range of motion. Theproximal end is closed, preferably by an integral seal.

Yet another embodiment is provided in a method for training comprising:

-   grasping a flexible swing stick with at least one hand at a proximal    end wherein the flexible swing stick comprises:-   a hollow tube comprising a distal end and the proximal end wherein    at least the distal end is closed by an integral seal;-   at least one slidably received weight is in the hollow tube disposed    to move from the proximal end to the distal end when the flexible    swing stick is swung through at least a portion of a range of    motion; and-   wherein the proximal end is closed;-   with the slidably received weight at the proximal end moving to the    distal end upon swinging the flexible swing stick through the range    of motion wherein the range of motion comprises a narrow portion;    and-   wherein the slidably received weight impacts the distal end within    the narrow portion of the range of motion;-   when swinging the flexible swing stick through at least a portion of    the range of motion.

Yet another embodiment is provided in a method for forming a flexibleswing stick. The method includes providing a hollow tube comprising aproximal end and a distal end and forming an integral seal on at leastthe distal end. Inserting at least one slidably receivable weight in thetube prior to either the forming of the integral seal on the proximalend or sealing of the proximal end.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 is a cross-sectional schematic view of an embodiment of theinvention.

FIG. 2 is a partial cut-away schematic view of an embodiment of theinvention.

FIG. 3 is a schematic representation of the process of manufacturing anembodiment of the invention.

FIG. 4 is a cross-sectional side view of a representative mold for usein manufacturing an embodiment of the invention.

FIGS. 5-7 are sequential representations of an embodiment of the methodof using the invention.

FIG. 8 is a schematic representation illustrating the narrow portion ofa swing that is inside the larger range of motion of the swing.

DESCRIPTION

The instant invention is related to a flexible swing stick and methodsof using the flexible swing stick for training primarily the wrists,hands and arms to swing a club with more consistency. More specifically,the flexible swing stick, and method of training, allows for training ofthe fast twitch muscles that control primarily wrist, hand and armmovement such that a person is able to swing a club faster, particularlywhere wrist movement during the swinging motion is critical, therebyproviding stimulation for the person's relevant proprioceptors.

Throughout the description the term “club” is used to refer to sportingitems typically used to hit an object such as a ball. Particularlypreferred clubs are those used to hit or throw a ball or object such asin baseball, softball, golf, cricket, tennis, badminton, lacrosse, fieldhockey, ice hockey, racquetball, squash, pickleball, table tennis andthe like. The invention is particularly suitable for training for theuse of clubs which have a range of motion wherein a narrow range of thebroader range of motion is intended to move the club at a highervelocity than the velocity outside of the narrow range such as theincreased velocity achieved by involvement of the wrist during a portionof a swing which is otherwise primarily a swing of the arms and torso.

The instant invention is related to a flexible swing stick comprising aflexible elongated hollow tube with closed, preferably integrallysealed, ends containing weighted objects inside the hollow tube. Theweighted objects are free to move inside the hollow tube for at least aportion of the length of the hollow tube. In use, the hollow tube isgrasped at a proximal end by at least one hand and moved in a simulatedswinging motion thereby allowing for the simultaneous training of theneuromuscular system and fast twitch muscles associated with theswinging motion. Effective use of the instant invention results in anincrease in the physical awareness of the involved body parts during theswinging motion and significantly enhances the ability of an athlete toswing a club more effectively. More specifically, the present inventionenables an individual to train for enhanced control, improvedconsistency and increased speed in the swinging motion by providingauditory and physical feed-back at the simulated position of impact withthe ball or object which is within the narrow portion of the range ofmotion without having to actually hit, strike or throw a ball or object.

Improved training devices and methods of training are constantly beingdeveloped by professionals in all sports with one of the goals being toenhance the performance of the athlete. Swinging of a club is common tomany sports such as baseball, softball, golf, cricket, tennis,badminton, lacrosse, field hockey, ice hockey, racquetball, squash,pickleball, table tennis and the like. It is an objective of thisinvention to provide a training device with the ability to enhance thetraining of an athlete's swinging motion by stimulating the athlete'sfast twitch muscles that control the actions of primarily the wrists,hands and arms, and to enhance the athlete's sensory receptors in themuscles, tendons, ligaments and joints thereby enabling improved musclemovement in the swinging motion for a more precise swinging motion andenhanced power. A particular feature is the incorporation of vestibularfeedback of feel and sound when swinging and oscillating the devicethereby enabling the athlete to have a greater awareness of the positionof their wrists, hands and arms at the point in their swing wherecontact with a ball or object approximately occurs enabling them to makemore effective corrections and adjustments to their swing.

Proprioception and kinesthesia, the sensation of joint motion andacceleration, are the sensory feedback mechanisms for motor control andposture. These mechanisms work in concert with the vestibular system,which is a fluid filled network within the inner ear, that can feel thepull of gravity and helps the body keep oriented and balanced. Theproprioception, kinesthesia and vestibular system work in concert toprovide a constant influx of sensory information allowing for immediateand unconscious adjustments to the muscles and joints in order toachieve movement and balance.

Proprioception is the process by which the body can vary musclecontraction in immediate response to incoming information regardingexternal forces by utilizing stretch receptors in the muscles to providefeedback of the joint position in the body. Proprioceptors in the jointsand where the tendons meet the muscles allow a person to be more awareof the coordination of the various muscles, joints and limbs that areinvolved in motion.

The proprioception sensory system utilizes proprioceptors in the musclesthat monitor length, tension, pressure, and noxious stimuli. The musclespindles, the most complex and studied of the proprioceptors, informsother neurons of the length of the muscle and the velocity of thestretch. The density of muscle spindles within a muscle increases formuscles involved in fine movements, as opposed to those involved inlarger course movements. The brain utilizes input from many of thesespindles and registers changes in angle and position that the muscle hasaccomplished. Spindles found in the arm and leg muscles, for example,aid in maintaining posture against gravity.

Another proprioceptor, the golgi tendon organ, is found where thetendons meet the muscle. They send detailed information about thetension occurring in specific parts of the muscle. There are alsoproprioceptors sending information to the nervous system from joints andligaments. Depending on the amount, where in the body, and from whatproprioceptors the different input is coming from, determines if theinformation will be made conscious or processed unconsciously. All theinput coming into the nervous system is processed, and then depending onthe state of the muscle, commands are sent back to the muscle.

The initiation of proprioception is the activation of a proprioreceptorin the periphery. The proprioceptive sense is believed to be composed ofinformation from sensory neurons located in the inner ear, for motionand orientation, and in the stretch receptors located in the muscles andthe joint-supporting ligaments. There are specific nerve receptors forthis form of perception termed “proprioreceptors”, just as there arespecific receptors for pressure, light, temperature, sound, and othersensory experiences. Proprioreceptors are sometimes known as adequatestimuli receptors.

Muscles have a combination of slow twitch and fast twitch muscle fibers.If a muscle can be fatigued quickly during rapid oscillatory use, thenthose muscles would have a high percentage of fast twitch muscle fiberwith Type I IX being the largest of the fast twitch. It is known in thefield of Exercise Science that moving a weighted object back-n-forthrapidly for a short amount of time is all that is required for anathlete to condition and stimulate the fast twitch muscles within themuscles being used. The light weight of the flexible swing stickcombined with its flexibility allows for the use to condition andstimulate the fast twitch muscles that control primarily wrist, hand andarm movement in this application. Further, exercise science tells usthat rapid back and forth oscillation has a positive effect on theenhancement of joint proprioception. Rapid oscillation in a back andforth manner of the instant invention can have a positive effect on anathlete's joint proprioception which can enable the athlete to developenhanced dynamic joint stability and enhanced neuromuscular control thatare useful when swinging a club. The combination of the sensory feedbackof feel and sound upon impact of the moving weights within the flexibleswing stick and the conditioning and stimulating of the sensoryreceptors, or proprioceptors, during the swinging motion is believed toprovide the user of the flexible swing stick with an enhanced ability toboth understand their swing and make corrections/adjustments to theirswing in order to enhance their ability to strike the ball or objectmore accurately when they play their sport.

The flexible swing stick and method of using the present inventiontherefore allows for training of the proprioreceptors in concert withthe muscles.

The flexible swing stick of the invention will be described withreference to the various figures which are included for the purpose ofdescribing the invention without limit thereto. Throughout the inventionsimilar elements will be numbered accordingly.

An embodiment of the invention will be described with reference to FIGS.1 and 2. FIG. 1 is a schematic view of the flexible swing stick showingthe various material components used in the construction of the flexibleswing stick. The surface treatment and surface tape are excluded fromFIG. 1 for clarity. FIG. 2 is a partial cut-away schematic view of theflexible swing stick. The flexible swing stick, 10, has a preferredlength of at least about 10″ to no more than about 70″, preferablyweighing at least 10 to no more than 2000 grams, more preferably atleast 225 to no more than 1000 grams and even more preferably at least300 to no more than 700 grams. The flexible swing stick comprises ahollow tube, 22, with at least one end being closed by the applicationof heat, pressure, and molding to form an integrally sealed distal end,19. An optional rod, 18, is within the hollow tube along with at leastone slidably received weight, 14, and an optional flexible spacer, 15.An ⅛″ diameter steel rod is suitable for demonstration of the invention.A steel ball a suitable slidably received weight for demonstration ofthe invention. A foam flexible tube, preferably about ⅝″ in diameter, issuitable for demonstration of the invention. Foam flexible tubestypically have a natural curvature, often referred to in the art as rollset curl, resulting from the coiling of the tube. Natural curvature isobserved when a tube is non-linear in an unperturbed state. Thecurvature provides some friction between the surface of the foam tubeand the inside diameter of tube to keep the flexible spacer from movingas easily as the slidably received weights move within the tube. Aswould be realized from FIG. 1, the slidably received weights move inresponse to motion of the flexible swing stick with the stiffness of theflexible swing stick and rate of motion of the slidably received weightsoptimized by the effective choice of the rod and the length of motionwithin the length of the tube which is limited by the flexible spacer.

The proximal end of the tube, 11, is preferably an integrally sealedproximal end as will be described further herein. An optional butpreferred cap, 12, over the proximal end is provided for aesthetics andto aid in hand placement or to mimic the club being simulated. Aconventional, and widely available, thermoplastic rubber crutch tippushed onto the end of the tube and held in place using a glue issuitable for use as an end cap. An optional but preferred surfacetreatment, 16, such as a wrap is provided for aesthetics and to improvethe ability of the flexible swing stick to mimic the feel of the clubfor which the training is intended. A conventional, and widelyavailable, peel-n-stick foil faced tape is suitable for demonstration ofthe invention. The surface treatment, preferably a wrap, can be appliedto cover the entire circumference of the tube from near the end of theproximal end and part of the way down the length of the tube towards thedistal end to improve the ability of the flexible tube to resistbuckling if the flexible swing stick is swung and stopped abruptlyduring the swinging action as is typical in some training exercises asdetailed further herein. A surface tape, 17, can be applied over thewrap, 16, preferably extending over the applied length of the previouslyapplied wrap for the purpose of providing a gripping surface with adiameter and feel mimicking that of the intended club.

A method of manufacturing the flexible swing stick will be describedwith reference to FIG. 3. In FIG. 3 a hollow tube precursor, 221, isillustrated prior to processing. The preferred hollow tube precursor isthermoplastic tube which is hollow in the center and open at both ends,25. To make the end of the hollow tube formable heat is applied to oneend of the hollow tube precursor such that the heat is sufficient tocause the end of the hollow tube to become soft and appear almost liquidin appearance. Through a series of sequential manipulations the softenedhollow tube is bonded across the opening, preferably using a mechanicaldevice, such as a pair of pliers, to fuse opposite sides to form atleast one fusion site, 23, which may also form a flaired section, 27,which is wider than the outside diameter (OD) of the hollow tubeprecursor. The flaired section can then be reduced to about the same asthe OD as illustrated at 26. Ultimately, the integrally sealed distalend, 19, for example, is formed by heating and fusing the hollow tubeprecursor. The integral sealed end prohibits an optional rod, 18,optional flexible spacer, 15, and slidably received weights, 14, fromexiting the hollow tube.

At least a portion of the outside of the hollow tube is preferablycovered a surface treatment, 16, which may be an applied coating or awrap. An applied coating is a material which is applied as a flowingchemical such as by a dip, spray or spread-on material, and a wrap is amaterial which is adhesively applied such as from a strip. The surfacetreatment is preferred to improve the grip, aesthetics, durability,stiffness or friction of the exterior of the hollow tube. A secondsurface treatment, 17, may be applied which may be an applied coating ora wrap. An applied coating is a material which is applied as a flowingchemical such as by a dip, spray or spread-on material, and a wrap is amaterial which is adhesively applied. Either surface treatment may be anadhesively bonded wrap such as a bat grip tape, 17, that is spirallywound around the circumference of the hollow tube, 22, starting at theproximal end, 11, for a distance axially down the length of the hollowtube, 22, at least covering the previously applied surface treatment,16. The second surface treatment, 17, is preferred to improve the grip,aesthetics, durability, stiffness or friction of the exterior of thehollow tube.

In another embodiment the end of the hollow tube precursor is heated tothe degree necessary for the hollow tube to fuse. The heated hollow tubeprecursor is placed in a device which forms the heated thermoplasticinto an integrally sealed end. For the purposes of this description theterm “integrally sealed” or an “integral seal” is used to define ahollow tube, with at least one end sealed wherein the seal is the samematerial as the hollow tube and the outside dimension of the hollow tubeis substantially maintained.

With further reference to FIG. 3, the opposing sides of the heated tube,222, are brought together with direct surface to surface contactpreferably along the centerline of the hollow tube with enough pressureto force the two inside surfaces of the heated tube to come in contactfor a time of about 5 seconds over an area about ¼ square inch where thehollow tube will fuse to itself, such as at that ¼ square inch position,as illustrated at 23 in FIG. 3B. This action will cause the end of theheated tube to flair out such that the cross-section of the flairexceeds beyond the OD of the heated tube. As illustrated in FIG. 3C thepreviously flared end, 27, having been heated with pressure applied tothe outside edges, 27, of the heated tube such that the reformed end,26, has no cross-sectional dimension greater than the original outsidediameter of the hollow tube, 221, is molded to a smooth finished shapeby the application of heat applied to the reformed end of the tube, 26,until the reformed end of the hollow tube and the immediate sides of thehollow tube near the end of the hollow tube, 26, are hot with thesurface of the thermoplastic material becoming almost liquid inappearance. The hot end, 222, is inserted into the open end of the mold,31, illustrated in FIG. 4 for a time preferably between 5 and 20 secondswith pressure applied axially to a section of the tube beyond the heatedend thereby allowing the heated and partially fused end to conform tothe shape of the interior of the mold. After cooling the integral seal,119, is obtained with the original opening completely closed afterformation of the integral seal.

FIG. 4 is a schematic side view of an embodiment of a mold used to shapeand close the reformed or fused hollow tube by placing the hot end ofthe reformed hollow tube inside the open end of the mold, 31, andapplying pressure to a portion of the end of the tube that is outsidethe open cavity of the mold, 31, axially along the length of the tube toforce the hot hollow tube of the reformed end to conform to thedimensions of the inside of the mold, 31, thereby closing the end toform an integrally sealed end. An integral part of the repeated safe useof the flexible swing stick with the repeated impact of the slidableweights, 14, against the distal integrally sealed end, 119, is themethod of fabricating at least one open end of a thermoplastic tube,without the use of glues or mechanical devices such as screws. The moldis represented as the open cavity of a threaded PVC bolt.

After forming the integral sealed end the internal components, asdescribed relative to FIGS. 1 and 2, can be inserted into the hollowtube and the other end sealed, preferably, to also form an integrallysealed end.

The flexibility of the flexible swing stick in combination with theslidably received weights therein permits the flexible swing stick to beused in an oscillatory manner by holding the flexible swing stick at ornear the handle, or proximal, end within the narrow portion of the rangeof motion. Swinging the flexible swing stick and incorporatingoscillation within the narrow portion of the swing conditions andstimulates the fast twitch muscles of the wrist and forearms to train auser to move their wrists and their arms quicker and faster during theswinging motion. This oscillatory movement may be done at any positionthat the user selects within the range of motion thereby training themuscles and proprioceptors in any portion of the range of motion.Alternatively, when combined with the act of swinging the flexible swingstick, the user will abruptly stop their swinging motion part of the waythrough their swing, such as within the narrow portion, which appliesforces at the proximal end of the flexible swing stick for several veryshort rapid back-n-forth movements. The rapid deacceleration coupledwith several very short rapid back-n-forth movements causes theopposite, or distal, end of the flexible swing stick to oscillate in aback and forth manner. This motion mimics a throwing motionrepresentative of the motion used in lacrosse, for example. The flexibleswing stick is preferably oscillated back and forth with the length ofthe back and forth movement of the wrists small in the range of lessthan 1 inch up to approximately 3 inches at the proximal end of theflexible swing stick. Resuming the swing through to the end of the rangeof motion of the swing, after the oscillatory movement, produces acombination of benefits including fast twitch muscle activation andstimulation of the appropriate sensory receptors, or proprioceptors, forimproved joint mobility. Vestibular feedback of feel and sound at impactof the slidably received weights at the distal end can allow the user tohave a better sense of the position of their wrists, hands and arms atthis critical impact position which can allow the user to betterunderstand their current swing and make corrections and improvements totheir swinging motion. Stopping of the swinging movement part of the waythrough the range of motion preferably occurs at about the time when theuser feels and hears the impact of the weighted objects inside theflexible swing stick striking the inside of the distal end of theflexible swing stick.

In a particular use, the flexible swing stick is held by the user withat least one hand positioned at or near the proximal end of the flexibleswing stick and at a position along the swinging path of the flexibleswing stick where the weights inside the flexible swing stick are freeto move inside the flexible swing stick. During the beginning of theexercise the slidably received weights are positioned at the proximalend of the flexible swing stick. As the flexible swing stick transitionsthrough the range of motion the slidably received weights move to thedistal end of the flexible swing stick and upon impact with the insideof the distal end of the flexible swing stick with the swing beingabruptly stopped and followed by several back-n-forth oscillations atthe proximal end of the flexible swing stick stimulates and conditionsthe fast twitch muscles in the user's forearms and wrists due to theoscillating frequency and amplitude of the opposite, distal, end of theflexible swing stick with resistance increasing as the frequency of backand forth movement of the hands and arms increases.

The hollow tube is preferably a plastic material such as polypropylene.In a particularly preferred embodiment the polypropylene has a flexuralmodulus of between 100,000 psi and 400,000 psi. The hollow tube ispreferably produced by the extrusion process and preferably has a smoothrounded interior. The hollow tube has a preferred OD of 0.70″ to 2″. Useof a material with a flexural modulus of greater than 1000 psi isdesired with an upper limit of the flexural modulus of 10,000,000 psi.The outside diameter of the flexible swing stick is preferably from atleast ½″ to more than 3″ and the wall thickness is preferably at least0.05″ to no more than 0.25″. Particularly preferred hollow tubes featureunreinforced extruded thermoplastic tubes or reinforced thermoplastic orthermoset resin tubes using continuous glass or carbon fibers producedby a variety of processes including filament winding, pultrusion,braided sleeves impregnated with a resin over a mandrel, B-stagedcontinuous glass or carbon fiber tape wrapped over a mandrel and curedwith heat and pressure or other composite processing method. In order toachieve the desired flexibility and durability of the tube used in theconstruction of the flexible swing stick the hollow tube can beengineered by selecting fibers, resins, orientation of fibers, outsideand inside diameter of the tube, consistent outside and inside diameterthe length of the tube or a tapered tube, length of the tube to producea tube that will provide suitable flexibility and durability. Thefollowing combination of variables produces a tube that functionsacceptability in the construction of the flexible swing stick: anextruded unreinforced thermoplastic hollow tube using a ‘no brake’polypropylene resin formula from Hudson Extrusions, Inc. with an outsidediameter of 0.890″ and an inside diameter of 0.715″ with a length ofbetween 34 and 36 inches with both ends of the tube closed using thepreviously described process of fusing and molding both ends of thetube. Using a flexural bending modulus of 150,000 psi for the Hudson ‘nobrake’ polypropylene along, the EI (or stiffness) of this tubecalculates to be 2696 lbs-int.

The slidably received weights are preferably round in shape andpartially fill the inside of the flexible tube with enough space toallow for movement inside the tube. The slidably received weights insidethe flexible swing stick are preferably metal with a diameter of atleast 0.154″ to no more than 0.625″ with steel shot or steel balls beingpreferred and 4.5 mm (0.18″) BB's acceptable.

An optional, but preferred flexible spacer, such as a length of roundfoam backer rod or the like, placed inside the tube between theparticles and the proximal end of the flexible swing stick reduces thelength that the particles may travel inside the tube for the purpose ofadjusting the point of impact during the swinging of the flexible swingstick. If the space in the interior for the particles to move is filledless than full, this permits the particles to move and create thedynamic action of impact that is desired when the arms and hands aremoved in swinging the flexible swing stick.

An optional but preferred rod can be used to limit the flexibility ofthe flexible swing stick. A ⅛″ diameter carbon steel rod with a lengthabout ½″ less than the inside length of the thermoplastic tube issuitable for demonstration of the invention. The stiffness, or EI, ofthe ⅛″ diameter carbon steel rod with an E=30,000,000 psi is 359lbs-int. It is desirable that the EI of the extruded unreinforcedthermoplastic hollow tube is greater than the rod.

The total weight of the flexible swing stick is approximately the weightof the club being trained for and is preferably at least about 10 gramsto no more than about 1000 grams and more preferably at least about 300grams to no more than about 700 grams. To simulate a softball bat, or a7-iron golf club, about 400 grams is optimal for most users.

An embodiment of the method of use of the invention will be describedwith reference to FIGS. 5-7. In FIG. 5 the flexible swing stick, 10, ispreferably held by 2 hands, 21, of the user, as in a golf grip, at theproximal end of the flexible swing stick, 10. The slidably receivedweights, 14, are persuaded towards the proximal end and are in contactwith the flexible spacer, 15, if used. As the user swings the flexibleswing stick through the range of motion as shown by the arrows, 33, inFIG. 6, the slidably received weights, 14, move towards the distal end,29, of the flexible swing stick contacting the interior of the hollowtube at the integral sealed end, 19. The slidably received weights, 14,preferably impact the distal end of the flexible swing stick,10, at atime during the downward swinging motion as in FIG. 6 preferablycorresponding to the narrow portion of the range of motion when the userswings the flexible swing stick from the top of their swing in adownward motion towards the bottom of their swing with a follow-thru asin FIG. 7 to completion of the swing. The illustrations of FIGS. 5-7 arerepresentative of a baseball swing, a golf swing or many other swingmotions for a club with the difference being the plane within which theclub swings.

FIG. 8 illustrates the range of motion, 300, through which a clubtransits in a typical swing. It is preferable, in most instances, thatthe range of motion remain in a plane. The narrow portion, 301,represents the region with a higher club velocity than the regions oneither side thereof. In some swings the range of motion may exceed 360°.

When the flexible swing stick is swung the distal end of the flexibleswing stick can vary from a very slow speed to very high speeds withspeeds exceeding 100 miles per hour not uncommon. In golf, the averageclub head speed for an average golfer is about 80 miles per hours withinthe narrow portion of the range of motion. A professional baseballplayer can have a bat speed of well over 100 miles per hour within thenarrow portion of the range of motion. Therefore, it is essential thatthe distal end of this flexible swing stick have sufficient structuralintegrity to withstand many impacts of the slidably received weightsimpacting the distal end of the flexible swing stick. The thermoplasticmaterial selected is preferably able to fuse to itself under the correctheat and correct pressure with the reheating insuring that the previousheating and pressure allows the material to fully fuse. Both ends of theflexible swing stick may be fully fused in like manner.

The material of construction for the hollow tube is selected to make theflexible swing stick light in weight, flexible to bend without buckling,flexible to be able to be oscillated back and forth rapidly andresistant to impact damage from impact by the slidably received weightsfast impingement. It is important that the flexible swing stick have adegree of flexibility but not be too flexible. Significant bendingforces are exerted when the flexible elongated flexible swing stick isswung fast and it is important that this flexible swing stick be lightweight such that the flexible swing stick can be swung as fast as theathlete swings their normal club. It is important for the user to hearand feel the impact of the slidably received weights impacting theopposite end of the flexible swing stick, called vestibular feedback,when the flexible swing stick is swung and impact within the hollow tubeof the flexible swing stick occurs. The mind of the user obtains abetter sense of their swing when they can hear and feel the impact ofthe slidably received weights impacting the distal end of the flexibleswing stick in much the same way as the user hears and feels the impactwhen actually hitting a ball or object. With this flexible swing stick,the act of hitting or throwing the ball or object is removed, and theuser can mentally focus on their swing motion and be consciously awareof the impact sound and feel. Also, a trained coach can hear the soundand see the person's swing and can mentally correlate the two vestibularinputs to help coach the player to improve the athlete's swing.

In many instances a coach may want an athlete to stop the flexible swingstick part way through the swing for a variety of reasons includingmimicking a throw. The stopping action can produce significant stress onthe hands and arms so a tailored degree of flexibility in the flexibleswing stick is important. Also, a flexible material will be lessdamaging to one's joints than a rigid device such as an aluminum orwooden bar or steel or graphite shafted golf club. The length of theflexible swing stick is preferably between at least 10″ to no more than70″ and more preferably at least 20″ to no more than 40″.

When a player stops their swinging motion part way thru their swingsignificant bending forces are exerted on the thermoplastic tube of theflexible swing stick. A typical bat grip tape as the outside wrap at thehandle end of the flexible swing stick and the length of this wrap ofabout 9 inches from the proximal end protects against the hollow tubefrom buckling. To further minimize buckling, a first wrap of afoil-faced or fabric reinforced adhesively backed tape is applied fromthe handle, or proximal, end of the flexible swing stick to a positionjust inside the wrap of the bat grip tape around the circumference ofthe hollow tube. This foil backed or fabric reinforced tape providessignificant resistance to buckling while at the same time not addingundue weight to the flexible swing stick. To further limit the tendencyof the flexible swing stick to buckle rod, a ⅛″ diameter carbon steelrod with a length preferably of less than about ½″ less than the insidelength of the thermoplastic tube after the closing of both ends, may beused. The rod limits the oscillation amplitude of the impact end of theflexible swing stick, when the person stops their swing part way thrutheir swinging motion, and this limiting of the oscillation amplitudereduces buckling at or near the hand position. If the user swings hardenough to cause buckling to occur, the selection of an extruded ‘nobrake’ polypropylene material as the material for the extrudedthermoplastic tube has shown to insure that the hollow tube only crimpsat the buckling location and does not tear or rip with all of thematerials inside the thermoplastic tube remaining inside the hollow tubeand not exiting the hollow tube where they may injure someone.

The distal end of the flexible swing stick may also be oscillated backand forth, by the user holding the flexible swing stick with at leastone hand at the proximal end of the flexible swing stick, followed bymovement of just the user's wrists in an articulating manner side toside or up and down or by movement of the user's wrists, hand and arm inunison in a side to side or up and down manner which may include anindependent articulating movement of the wrists at the same time thatthe wrist, hand and arm are moving side to side or up and down inunison. Exercise professionals state that if a given muscle, such as thewrist or forearm, can be fatigued in a short period of time, between 5and 30 seconds, thru a repetitive motion, either back and forth, up anddown or in a circle or elliptical pattern, where the load on the musclesis significant but not damaging, then there are fast twitch musclesfibers in that muscle. Rapid oscillation thru a repetitive motion,either back and forth, side to side or up and down, under an appropriateload or resistance, defines a proven method of conditioning andstimulating the fast twitch muscle fibers in the muscles being used toactivate the rapid oscillation. Conditioning and stimulating the fasttwitch muscle fibers will enable a person to swing a club faster and ifthe club is swung faster, then the ball or object has the chance to havea higher velocity due to being struck or thrown optimally. This methodof oscillating the flexible swing stick by holding it at the proximalend, as described above, may be performed at any location along theswinging motion or in the case where the person stops their swing partway through their swing, the oscillation may be performed for a shortperiod of time, at that position, with the person completing their swingfollowing the oscillation. In this method where the swinging motion isstopped and the flexible swing stick oscillated followed by completionof the swing will not only condition and stimulate the fast twitchmuscle fibers but when the swing is stopped an impact of the slidablyreceived weights inside the flexible swing stick occurs providing thevestibular feedback of feel from impact and the sound from impact.Together, significant enhancement can occur to improving the swing ofthe person or athlete.

EXAMPLES Example A

A 32¾″ ‘no brake’ formula thermoplastic polypropylene unpigmentedextruded tubing with an outside diameter of 0.890″ and an insidediameter of 0.715″ from Hudson Extrusions Inc.; Hudson, Ohio was used asa hollow tube.

Both ends of the elongated thermoplastic extruded tubing were closed forsafe and effective use wherein at least one end, used as the distal end,is formed as an integrally sealed end without the use of glues ormechanical devices such as screws clamps, end caps, etc. To form theintegrally sealed end the thermoplastic tube was heated using a heatgun, such as Intertek VT-1000 heat gun, for about 15 seconds followedquickly by the application of a controlled amount of pressure for about5 seconds using a clamping device such as a pair of pliers, to bring incontact or pinch together and fusing two opposite sides of the insidediameter of the open end of the thermoplastic tube. The pressure wasapplied to the outside diameter of the thermoplastic tube atapproximately the centerline of the tube for a contact area of about ¼square inch to fuse the two opposing sections of the inside diameter ofthe thermoplastic tube to each other creating a flattened end of thethermoplastic tube. While the fused end of the tube was still hot, butwith the clamps removed, pressure was applied to the outside diameteredges of the major axis of the flattened end of the thermoplastic tubetowards each other using a clamping device such as a pair of pliers suchthat the flattened end with fused section is further reshaped such thatno exterior dimension of the reshaped end of the tube is greater thanthe original OD of the tube. Using the heat gun, the end was reheatedfor about 15 seconds to reheat the reshaped end of the thermoplastictube followed by insertion of the reheated and reshaped end ofthermoplastic tube into the open end of a round mold. A threaded ornon-threaded hex-head ¾″ PVC bolt made by LASCO, and sold at Lowes, Inc.is a suitable round mold. An adequate amount of pressure was applied tothe opposite end of the tube to compress and mold the reheated andreshaped end of the tube to the inside dimensions of the mold therebycreating a molded closed end as an integral seal which is able to resistthe repeated impact of the slidably received weights.

After allowing the integral seal to cool, for approximately 10 minutes,381 grams of 4.5 mm BB's by Daisy® were inserted into the open end andthe open end was fused and reshaped, in a manner similar to the processdescribed above, to form a second integral seal. A 0.843″×1.5″ black PVCend cap made by Stock Caps was applied over the end of the firstintegral seal. A #19 black crutch tip, supplied by Schacht-Pfister ofHuntington, Ind. was applied over the second integral seal. The #19crutch tip, previously applied was moved about ½″ towards the end of theflexible tube and a black cushioned bat grip tape, as manufactured byRawlings, was applied in a 45 degree spiral pattern around thecircumference of the flexible tube starting at the edge of the open endof the #19 crutch tip and extending approximately 9″ down the length ofthe flexible tube.

The weight of the finished flexible swing stick was about 445 grams andthe height of the BB's inside the hollow tube from the first fused endwas about 14″. The calculated distance inside the flexible tube for theBB's to move freely as the flexible swing stick was about 18.25″. Usinga simple cantilever beam deflection equation of, Deflection(inches)=[PL³ divided by (3*E*I)]−the deflection in inches can becomputed. The flexural modulus of the flexible thermoplasticpolypropylene ‘no brake’ tube is about 150,000 psi and the moment ofinertia (I) for the round shape with an OD of 0.89″ and ID of 0.715″ wascalculated to be 0.01797. Therefore, the deflection at the end of theflexible swing stick with a cantilever length of approximately 16.5″ is0.54″. This deflection was used as a reference for evaluating theflexibility and performance of the flexible swing stick when theflexible swing stick was swung or oscillated by users. In order for theflexible swing stick to be used properly, the BB's inside must be in aposition to move to the distal end during use. In baseball or golf, thedistal end is higher than the proximal end, as measured from the ground,so the BB's will be able to move freely to the distal end of theflexible swing stick during the swinging or oscillating of the flexibleswing stick.

Example A failed for use when tested as a baseball bat with the failuremode being a crimping of the flexible tube in the area of the tube thatwas wrapped with the bat grip tape. Further, it failed in the trainingdrill where the flexible swing stick was swung like a baseball bat butabout ½ way through the swing the user stopped the swing abruptly forthe purpose of oscillating the flexible swing stick back and forth atthat position for a number of times. The momentum generated by theabrupt stopping of the swinging action combined with the length of theflexible swing stick and the weight of the BB's was too much lateralbending force for the flexible tube to resist, and it crimped renderingthe flexible swing stick unusable for further use as a baseball batsimulator. But the ‘no break’ characteristics of the Hudson ‘no brake’material kept the flexible swing stick safe as no opening in the wall ofthe flexible swing stick was created for the BB's to escape. In otherapplications Example A would be suitable for use.

Example B

A flexible swing stick was prepared as in Example A with a 35″ hollowtube and 243 grams of 5/16″ diameter steel balls by B C Precision ballsfrom Amazon inserted into the open end of the flexible tube. A single,½″ diameter steel ball from BC Precision balls from Amazon was insertedinto the open end of the hollow tube. The 8 gram ½″ diameter steel ballprevented the smaller 5/16″ diameter steel balls from moving past itinside the hollow tube having an inside diameter of 0.715″. The ½″diameter steel balls removes the potential of a 5/16″ diameter steelball from becoming stuck or wedged between the outside diameter offlexible grey foam backer rod and the inside diameter of thethermoplastic tube. The function of the 5/16″ steel balls plus the ½″diameter steel ball is to add weight to the flexible swing stick plusthe steel balls are able to move freely back and forth inside the hollowtube as the flexible swing stick is swung or oscillated back and forth.A ⅝″ diameter×5.5″ long piece of flexible grey foam backer rod from M-DBuilding Product, Inc., Oklahoma City, Okla. was inserted into the openend of the thermoplastic tube and pushed, using a long wooden dowel rod,to the opposite end to be in contact with the steel shot. This was doneso that the heat from the heat gun would not melt the foam as theopposite, or proximal, end was fused. The open end was fused andreshaped as described relative to Example A. A 0.843″×1.5″ black PVC endcap made by Stock Caps was applied over the end of the flexible swingstick at the place where the first end was fused, reshaped and molded. A#19 black crutch tip, supplied by Schacht-Pfister of Huntington, Ind.was applied over the proximal end of the flexible swing stick. The #19crutch tip, previously applied was moved about ½″ towards the end of theflexible tube and a black cushioned bat grip tape, as manufactured byRawlings, was applied in a 45 degree spiral pattern around thecircumference of the flexible tube starting at the edge of the open endof the #19 crutch tip and extending approximately 9″ down the length ofthe flexible tube.

The weight of the finished flexible swing stick was 398 grams and theheight of the steel shot, the 5/16″ diameter steel shot, inside theflexible tube from the first fused end was 10.5″ which was significantlyless than the 14″ from Example A. The use of the flexible foam backerrod reduced the available length that the steel shot could move insidethe hollow tube which provided satisfactory feedback wherein the soundof the impacting steel balls occur at the centerline of the player'sbody when tested by a high school softball team. The use of backer rodgives a means to vary the impact position during a player's swing tomeet desired criteria.

This flexible swing stick also failed in use with the failure mode beinga crimping of the flexible tube in the area of the tube that was wrappedwith the bat grip tape at a position about 7″ from the handle, orproximal, end of the flexible swing stick. It failed in training, inthis application, where the flexible swing stick was swung like abaseball bat but about ½ way through the swing the user stopped theswing abruptly for the purpose of oscillating the flexible swing stickback and forth at that position for a number of times. The momentumgenerated by the abrupt stopping of the swinging action combined withthe length of the flexible swing stick and the weight of the steel shotachieved too much lateral bending force for the flexible tube to resist.The tube crimped rendering the flexible swing stick unusable for furtheruse. Increasing the starting length of flexible thermoplastic tube to35″ was seen as a positive as this length was closer to the length of afemale softball bat as used in the intended test. But the ‘no break’characteristics of the Hudson ‘no brake’ material kept the flexibleswing stick safe as no opening in the wall of the flexible swing stickwas created for the steel balls to escape. The use of the largerdiameter 5/16″ steel balls was an improvement as the sound of theimpacting 5/16″ steel balls was louder and perceived as better than theimpact noise of the smaller BB's.

Example C

A flexible swing stick was prepared as in Example B with 48 grams of ⅝″diameter steel balls by BC Precision balls and 198 grams of ½″ diametersteel balls from BC Precision balls from Amazon. The ⅝″ diameter steelballs created a louder impact sound than either the 5/16″ steel balls orthe BB's when the flexible swing stick was swung. The function of the ⅝″diameter steel balls plus the ½″ diameter steel balls is to add weight.The louder sound of the steel balls making impact with the inside end ofthe flexible swing stick using just 3, ⅝″ diameter steel balls with theremainder of the weight of steel balls being ½″ diameter steel ballsallowed this construction of the flexible swing stick to be lighter inweight. A ⅝″ diameter×5.0″ long piece of flexible grey foam backer rodfrom M-D Building Product, Inc., Oklahoma City, Okla. was inserted intothe open end of the thermoplastic tube and pushed, using a long woodendowel rod, to the opposite end to be in contact with the ½″ diametersteel balls to insure the heat from the heat gun would not melt thebacker rod as the opposite end was integrally sealed. The open end ofthe flexible tube was fused and reshaped in a manner similar to theopposite end. A 0.843″×1.5″ black PVC end cap made by Stock Caps wasapplied over the end of the flexible swing stick at the end where thefirst end was fused, reshaped and molded. A #19 black crutch tip,supplied by Schacht-Pfister of Huntington, Ind. was applied over theother end of the flexible swing stick. The #19 crutch tip, previouslyapplied was moved about ½″ towards the end of the flexible tube and athicker bat grip tape, as manufactured by Rawlings, was applied in a 45degree spiral pattern around the circumference of the flexible tubestarting at the edge of the open end of the #19 crutch tip and extendingapproximately 9″ down the length of the flexible tube. The bat grip tapewas thicker than the bat grip tape used in Example B and was believed tooffer greater resistance to bucking in the handle area.

The weight of the finished flexible swing stick was 386 grams and theheight of the steel shot plus the back rod was 18.875″ leaving a lengthof 14.375″ for the steel shot to travel inside the flexible swing stick.The use of the flexible foam backer rod reduced the available lengththat the steel shot could move inside the thermoplastic tube and thissatisfied feedback from trials with the flexible swing stick where thecoach wanted the sound of the impacting steel balls to occur soonerduring the swinging of the bat by the player. In female softballtraining, some coaches want the player to make contact with the ball atthe position when the ball is about at the centerline of the player'sbody and the use of the backer rod gives a means to vary the impactposition during the player's swing.

This flexible swing stick also failed in use with a failure mode being acrimping of the flexible tube in the area of the tube that was wrappedwith the bat grip tape at a position about 7″ from the handle, orproximal, end of the flexible swing stick. It failed in training wherethe flexible swing stick was swung like a baseball bat but about ½ waythrough the swing the user stopped the swing abruptly for the purpose ofoscillating the flexible swing stick back and forth at that position fora number of times. This embodiment would be suitable for otherapplications.

Example D

A flexible swing stick was prepared, as in Example B, with a 35″ ‘nobrake’ formula thermoplastic polypropylene unpigmented extruded tubingwith an outside diameter of 0.890″ and an inside diameter of 0.715″ fromHudson Extrusions Inc.; Hudson, Ohio with 48 grams of ⅝″ diameter steelballs by B C Precision balls from Amazon inserted into the open end ofthe flexible tube and 168 grams of ½″ diameter steel balls from BCPrecision balls from Amazon. The ⅝″ diameter steel balls created alouder impact sound than either the 5/16″ steel balls or the BB's whenthe flexible swing stick was swung. The function of the ⅝″ diametersteel balls plus the ½″ diameter steel balls is to add weight plus thesteel balls are able to move freely back and forth inside the tube asthe flexible swing stick is swung or oscillated back and forth. Thelouder the sound of the steel balls making impact with the inside end ofthe flexible swing stick using just 3, ⅝″ diameter steel balls with theremainder of the weight of steel balls being ½″ diameter steel ballsallowed this construction to be lighter in weight than using all ⅝″diameter steel balls. A ⅝″ diameter×6.0″ long piece of flexible greyfoam backer rod from M-D Building Product, Inc., Oklahoma City, Okla.was inserted into the open end of the thermoplastic tube and pushed,using a long wooden dowel rod, to the opposite end of the tube to be incontact with the ½″ diameter steel balls to avoid subsequent heat damageas discussed above. A 0.843″×1.5″ black PVC end cap made by Stock Capswas applied over the end of first fused end. Two strips of 1″ wideGorrilla® duct tape were applied at the handle end of the flexible swingstick, starting about ½″ from the handle end of the flexible tube, downthe length of the flexible tube with the 2 strips positioned to providefor approximately the same space between the strips. A #19 black crutchtip, supplied by Schacht-Pfister of Huntington, Ind. was applied overthe handle end of and over the end of the previously applied strips ofGorilla® duct tape. A thicker bat grip tape, referred to as Lizard batgrip tape manufactured by Rawlings, was applied in a 45 degree spiralpattern around the circumference of the hollow tube starting at the edgeof the open end of the #19 crutch tip and over the previously appliedstrips of Gorilla® duct tape extending approximately 9″ down the lengthof the hollow tube to cover completely the strips of Gorilla® duct tape.

The weight of the finished flexible swing stick was 371 grams and theheight of the steel shot plus the backer rod was 18.375″ leaving alength of 15.125″ for the steel shot to travel inside the flexible swingstick. The use of the flexible foam backer rod reduced the availablelength that the steel shot could move inside the thermoplastic tube andthis satisfied feedback from previous trials with the flexible swingstick where the coach wanted the sound of the impacting steel balls tooccur sooner during the swinging of the bat by the player. The use ofthe backer rod gives a means to vary the impact position during theplayer's swing to meet the coach's needs.

With repeated use this embodiment did not fail.

Example E

A flexible swing stick was prepared, as in Example B, with a 35″ ‘nobrake’ formula thermoplastic polypropylene unpigmented extruded tubingwith an outside diameter of 0.890″ and an inside diameter of 0.715″ fromHudson Extrusions Inc.; Hudson, Ohio with 192 grams of ½″ diameter steelballs by B C Precision from Amazon and a ⅛″ diameter carbon steel rod incontact with the inside wall of the thermoplastic tubing. A ⅝″ diametersteel ball cannot be used as it will not fit inside the thermoplastictube with the ⅛″ diameter carbon steel inside. The sound of the steelballs making impact with the inside end of the thermoplastic tube is notas loud when using all ½″ diameter steel balls as compare to the use ofboth ⅝″ and ½″ diameter steel balls with the ⅝″ steel balls being thefirst steel balls to impact the inside end of the thermoplastic tube.The function of ½″ diameter steel balls is to add weight plus the steelballs are able to move freely back and forth inside the tube as theflexible swing stick is swung or oscillated back and forth which will beexplained later. A ⅝″ diameter×6.0″ long piece of flexible grey foambacker rod from M-D Building Product, Inc., Oklahoma City, Okla. wasinserted into the open end of the thermoplastic tube and in contact witha length of the surface of the ⅛″ diameter carbon steel rod and pushed,using a long wooden dowel rod, to the opposite end of the tube incontact with the ½″ diameter steel balls. This was done to avoid heatdamage as discussed above. A 0.843″×1.5″ black PVC end cap made by StockCaps was applied over the end of the flexible tube at the first fusedend of the thermoplastic tube. Two strips of 2.5″ wide 3M 3340 coldweather foil faced tape×9″ long were applied longitudinally to theoutside diameter length of the thermoplastic tube starting at thehandle, or proximal, end of the tube with the 2 strips applied such thatthey overlap approximately evenly creating total coverage of the outersurface of thermoplastic tube for the 9 inches from the handle end. A#19 black crutch tip, supplied by Schacht-Pfister of Huntington, Ind.was applied over the handle end of the flexible swing stick and over thepreviously applied strips of the 3M tape. Lizard bat grip tape, asmanufactured by Rawlings, was applied in a 45 degree spiral patternaround the circumference of the flexible tube starting at the edge ofthe open end of the #19 crutch tip and over the previously applied the3M tape strips.

The weight of the finished flexible swing stick was 400 grams and theheight of the steel shot plus the backer rod was 18″ leaving a length of15.25″ for the steel shot to travel inside the flexible swing stick. Theuse of the flexible foam backer rod reduced the available length thatthe steel shot could move longitudinally inside the hollow tube and thissatisfied feedback from previous trials using the flexible swing stickwhere the coach wanted the sound of the impacting steel balls to occursooner during the swinging of the bat by the player.

After extended use this embodiment did not fail.

Example F

A flexible swing stick was prepared, as in Example B, with a 35″ ‘nobrake’ formula thermoplastic polypropylene unpigmented extruded tubingwith an outside diameter of 0.890″ and an inside diameter of 0.715″ fromHudson Extrusions Inc.; Hudson, Ohio with 32 grams of ⅝″ diameter steelballs by B C Precision balls from Amazon are and 168 grams of ½″diameter steel balls from BC Precision balls from Amazon. The use of the⅝″ diameter steel balls created a louder impact sound than either the5/16″ steel balls or the BB's when the flexible swing stick was swung.The function of the ⅝″ diameter steel balls plus the ½″ diameter steelballs is to add weight plus the steel balls are able to move freely backand forth inside the tube as the flexible swing stick is swung oroscillated back and forth. The louder sound of the steel balls makingimpact with the inside end of the flexible swing stick using just 2, ⅝″diameter steel balls with the remainder of the weight of steel ballsbeing ½″ diameter steel balls allowed this construction of the flexibleswing stick to be lighter in weight than using all ⅝″ diameter steelballs. A ⅝″ diameter×7.0″ long piece of flexible grey foam backer rodfrom M-D Building Product, Inc., Oklahoma City, Okla. was inserted intothe open end of the thermoplastic tube and pushed, using a long woodendowel rod, to the opposite end of the tube to be in contact with the ½″diameter steel balls. A 0.843″×1.5″ black PVC end cap made by Stock Capswas applied over the fused end of the flexible swing stick at the endwhere the first end was fused, reshaped and molded. Two, 2.5″ widestrips of 3M 3340 cold weather foil faced tape×9″ long were appliedlongitudinally to the outside diameter length of the thermoplastic tubestarting at handle, or proximal end with the 2 strips applied such thatthey overlap approximately evenly creating total coverage of the outersurface of the thermoplastic tube for the 9 inches from the handle end.A #19 black crutch tip, supplied by Schacht-Pfister of Huntington, Ind.was applied over the handle, or proximal, end of flexible swing stickand over the previously applied strips of 3M tape. Lizard bat grip tape,as manufactured by Rawlings, was applied in a 45 degree spiral patternaround the circumference of the flexible tube starting at the edge ofthe open end of the #19 crutch tip and over the previously appliedstrips of 3M tape and extending approximately 9″ down the length of theflexible tube to cover completely the strips of 3M tape.

The weight of the finished flexible swing stick was 356 grams and theheight of the steel shot plus the backer rod was 18.75″ leaving a lengthof 14.50″ for the steel shot to travel inside the flexible swing stick.

After extended use this embodiment did not fail.

Example G

A flexible swing stick was prepared, as in Example B, with a 23″ ‘nobrake’ formula thermoplastic polypropylene unpigmented extruded tubingwith an outside diameter of 0.890″ and an inside diameter of 0.715″ fromHudson Extrusions Inc.; Hudson, Ohio as a practice device mimicking atennis racquet. The flexible swing stick utilized 168 grams of 5/16″steel balls by Moore Sales from Amazon and a 5″ long piece of foam backrod by M-D Building Products, Inc. of Oklahoma City, Okla. A 0.843″×1.5″black PVC end cap made by Stock Caps was applied over the end of theflexible swing stick where the first end was fused. A 5.25″ longexterior ground foam sleeve with ID=0.890″ from www.grabongrips.com wasslipped over the handle, or proximal end of the thermoplastic tube. A#19 black crutch tip, supplied by Schacht-Pfister of Huntington, Ind.was applied over the handle end using DAP Rapid Fuse™ All PurposeAdhesive by DAP Products, Inc. of Baltimore, Md. applied inside the #19crutch tip prior to pushing #19 crutch tip onto end of the thermoplastictube.

The weight of the finished flexible swing stick was 290 grams and theheight of the 5/16″ steel balls inside the flexible tube from the firstfused end was 7″. The calculated distance inside the flexible tube forthe steel balls to move freely as the flexible swing stick is used isabout 9.5″.

After extended use the embodiment did not fail.

Example H

A flexible swing stick was prepared, as in Example G, using a 26″ ‘nobrake’ formula thermoplastic polypropylene unpigmented extruded tubingwith an outside diameter of 0.890″ and an inside diameter of 0.715″ fromHudson Extrusions Inc.; Hudson, Ohio for use as a swing stick for youngfemale softball players in the range of 7 to 9 years of age as theseyoung players need to train with a device that is shorter than the 35″long swing sticks described above. The flexible swing stick utilized 48grams of ⅝″ steel balls by B C Precision balls from Amazon and 168 gramsof ½″ diameter steel balls from B C Precision balls from Amazon. No foambacker rod was used with this flexible swing stick.

A #19 black crutch tip, supplied by Schacht-Pfister of Huntington, Ind.was applied over the handle, or proximal, end using DAP Rapid Fuse™ AllPurpose Adhesive by DAP Products, Inc. of Baltimore, Md. applied insidethe #19 crutch tip prior to pushing the #19 crutch tip onto end of thethermoplastic tube. A Lizard bat grip tape, as manufactured by Rawlings,was applied in a 45 degree spiral pattern around the circumference ofthe flexible tube starting at the edge of the open end of the #19 crutchtip and extending approximately 9″ down the length of the flexiblethermoplastic tube.

After extended use this embodiment did not fail.

The invention has been described with reference to the preferredembodiments without limit thereto. One of skill in the art would realizeadditional embodiments and improvements which are not specificallystated but which are within the meets and bounds of the claims appendedhereto.

1. A flexible swing stick comprising; a hollow tube comprising a distalend and a proximal end wherein at least said distal end is closed by anintegral seal; at least one slidably received weight in said hollow tubedisposed to move from said proximal end to said distal end when saidflexible swing stick is swung through a range of motion; and whereinsaid proximal end is closed.
 2. The flexible swing stick of claim 1wherein said proximal end is closed by a second integral seal.
 3. Theflexible swing stick of claim 1 wherein said proximal end is closed byan end cap or plug.
 4. The flexible swing stick of claim 1 wherein saidhollow tube comprises a thermoplastic or thermoset polymer.
 5. Theflexible swing stick of claim 4 wherein said hollow tube comprisespolypropylene.
 6. The flexible swing stick of claim 1 wherein saidhollow tube has a flexural modulus of 1,000 to 10,000,000 psi.
 7. Theflexible swing stick of claim 6 wherein said hollow tube has a flexuralmodulus of 100,000 to 400,000 psi.
 8. The flexible swing stick of claim1 wherein said hollow tube has an outside diameter of at least 0.5″ tono more than 3″.
 9. The flexible swing stick of claim 1 wherein saidhollow tube has wall thickness of at least 0.05″ to no more than 0.25″.10. The flexible swing stick of claim 1 wherein said hollow tubecomprises a reinforced polymer.
 11. The flexible swing stick of claim 10wherein said reinforced polymer comprises a glass or carbon.
 12. Theflexible swing stick of claim 1 further comprising a flexible spacer insaid hollow tube.
 13. The flexible swing stick of claim 12 wherein saidflexible spacer has a curvature.
 14. The flexible swing stick of claim12 wherein said flexible spacer is between said proximal end and saidslidably received weight.
 15. The flexible swing stick of claim 1further comprising a rod in said hollow tube.
 16. The flexible swingstick of claim 15 wherein said rod has a stiffness or EI less than thatof said hollow tube.
 17. The flexible swing stick of claim 16 whereinsaid rod has a stiffness or EI less than ½ of said hollow tube.
 18. Theflexible swing stick of claim 1 wherein said slidably received weight isa ball.
 19. The flexible swing stick of claim 18 wherein said ball is ametal ball.
 20. The flexible swing stick of claim 19 wherein said ballis a stainless steel ball.
 21. The flexible swing stick of claim 18wherein said ball has a diameter of at least 0.154 to no more than0.625.
 22. The flexible swing stick of claim 1 further comprising asurface treatment.
 23. The flexible swing stick of claim 22 wherein saidsurface treatment comprises a wrap on an exterior surface of said hollowtube.
 24. The flexible swing stick of claim 23 wherein said wrap isselected from peel-n-stick foil faced metal tape, adhesively bondedfabric tape and peel-n-stick spiral wrapped bat tape.
 25. The flexibleswing stick of claim 24 further comprising a tape over said wrap. 26.The flexible swing stick of claim 1 having a length of at least 10″ tono more than 70″.
 27. The flexible swing stick of claim 26 wherein saidlength is at least 20″ to no more than 40″.
 28. The flexible swing stickof claim 1 having a weight of at least 10 grams to no more than 2000.29. The flexible swing stick of claim 28 having a weight of at least 225grams to no more than
 1000. 30. The flexible swing stick of claim 29having a weight of at least 300 grams to no more than
 700. 31. Theflexible swing stick of claim 29 further comprising an end cap.
 32. Amethod for training comprising: grasping a flexible swing stick with atleast one hand at a proximal end wherein said flexible swing stickcomprises: a hollow tube comprising a distal end and said proximal endwherein at least said distal end is closed by an integral seal; at leastone slidably received weight in said hollow tube disposed to move fromsaid proximal end to said distal end when said flexible swing stick isswung through at least a portion of a range of motion; and wherein saidproximal end is closed; with said slidably received weight at saidproximal end moving to said distal end upon swinging said flexible swingstick through said range of motion wherein said range of motioncomprises a narrow portion; and wherein said slidably received weightimpacts said distal end within said narrow portion of said range ofmotion; when swinging said flexible swing stick through at least aportion of said range of motion. 33-65. (canceled)
 66. A method forforming a flexible swing stick comprising: providing a hollow tubecomprising a proximal end and a distal end; forming an integral seal onat least said distal end; sealing said proximal end; and inserting atleast one slidably receivable weight in said tube prior to either saidforming of said integral seal or said sealing of said proximal end.67-97. (canceled)